Good Colorado pronghorn. It is a little hard to see from the picture but his cutters must be well above his ears if he is in the 16" range. It looks like he keeps his mass up high too. Are his bases big?
I have seen (and shot) younger and smaller bucks that have horns that hook back. I am not sure that that has anything to do with age.
Pronghorn is a fun (low pressure) hunt. The older I get the more I like to hunt them.